Documentary about Birds vision, migration

Hi, In the year 1999-2000 I watched one documentary (may be produced by BBC), about birds. The documentary was about how birds see, what can they see (like earth's magnetic field, colors) how their visual perception is different from that of other animals so that they can travel thousands of kms and be back at the same place on winter/summer etc. I tried to search that documentary but could not find it. Does anybody know the link for this documentary, if you have it, could you please share it with us? Its really informative. thank you